<!--
Copyright (C) 2015 The Android Open Source Project

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->

<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="../bower_components/iron-a11y-keys-behavior/iron-a11y-keys-behavior.html">
<link rel="import" href="gr-ajax.html">
<link rel="import" href="gr-diff.html">

<dom-module id="gr-diff-view">
  <template>
    <style>
      :host {
        background-color: var(--view-background-color);
        display: block;
      }
      h3 {
        margin-top: 1em;
        padding: .75em var(--default-horizontal-margin);
      }
      .mainContainer {
        border-bottom: 1px solid #eee;
        border-collapse: collapse;
        border-top: 1px solid #eee;
        width: 100%;
      }
    </style>
    <gr-ajax id="changeDetailXHR"
        auto
        url="[[_computeChangeDetailPath(_changeNum)]]"
        params="[[_computeChangeDetailQueryParams()]]"
        last-response="{{_change}}"></gr-ajax>
    <gr-ajax id="filesXHR"
        auto
        url="[[_computeFilesPath(_changeNum, _patchRange.patchNum)]]"
        on-response="_handleFilesResponse"></gr-ajax>
    <h3>
      <a href$="[[_computeChangePath(_changeNum)]]">[[_changeNum]]</a><span>:</span>
      <span>[[_change.subject]]</span> — <span>[[params.path]]</span>
    </h3>
    <gr-diff id="diff"
        auto
        change-num="[[_changeNum]]"
        patch-range="[[_patchRange]]"
        path="[[_path]]"
        on-render="_handleDiffRender">
    </gr-diff>
  </template>
  <script>
  (function() {
    'use strict';

    Polymer({
      is: 'gr-diff-view',

      behaviors: [
        Polymer.IronA11yKeysBehavior
      ],

      properties: {
        keyEventTarget: {
          type: Object,
          value: function() {
            return document.body;
          },
        },
        /**
         * URL params passed from the router.
         */
        params: {
          type: Object,
          observer: '_paramsChanged',
        },
        _patchRange: Object,
        _change: Object,
        _changeNum: String,
        _diff: Object,
        _fileList: {
          type: Array,
          value: function() { return []; },
        },
        _path: String,
      },

      keyBindings: {
        '[ ] u': '_handleKey',
      },

      _handleKey: function(e) {
        if (util.shouldSupressKeyboardShortcut(e)) { return; }

        switch(e.detail.combo) {
          case '[':
            this._navToFile(this._fileList, -1);
            break;
          case ']':
            this._navToFile(this._fileList, 1);
            break;
          case 'u':
            if (this._changeNum) {
              page.show(this._computeChangePath(this._changeNum));
            }
            break;
        }
      },

      _handleDiffRender: function() {
        if (window.location.hash.length > 0) {
          this.$.diff.scrollToLine(
              parseInt(window.location.hash.substring(1), 10));
        }
      },

      _navToFile: function(fileList, direction) {
        if (fileList.length == 0) { return; }

        var idx = fileList.indexOf(this._path) + direction;
        if (idx < 0 || idx > fileList.length - 1) {
          page.show(this._computeChangePath(this._changeNum));
          return;
        }
        page.show(this._diffURL(this._changeNum,
                                this._patchRange.patchNum,
                                fileList[idx]));
      },

      _diffURL: function(changeNum, patchNum, path) {
        return '/c/' + changeNum + '/' + patchNum + '/' + path;
      },

      _paramsChanged: function(value) {
        this._changeNum = value.changeNum;
        this._patchRange = {
          patchNum: value.patchNum,
          basePatchNum: value.basePatchNum || 'PARENT',
        };
        this._path = value.path;

        // When navigating away from the page, there is a possibility that the
        // patch number is no longer a part of the URL (say when navigating to
        // the top-level change info view) and therefore undefined in `params`.
        if (!this._patchRange.patchNum) {
          return;
        }
      },

      _computeChangePath: function(changeNum) {
        return '/c/' + changeNum;
      },

      _computeChangeDetailPath: function(changeNum) {
        return '/changes/' + changeNum + '/detail';
      },

      _computeChangeDetailQueryParams: function() {
        return { O: Changes.listChangesOptionsToHex(
            Changes.ListChangesOption.ALL_REVISIONS
        )};
      },

      _computeFilesPath: function(changeNum, patchNum) {
        return Changes.baseURL(changeNum, patchNum) + '/files';
      },

      _handleFilesResponse: function(e, req) {
        this._fileList = Object.keys(e.detail.response).sort();
      },
    });
  })();
  </script>
</dom-module>